Outdoor-air ventilation context
Best time to ventilate: compare outdoor air-quality windows carefully
AirAgora can compare outdoor modeled periods that may inform when to open windows. It does not measure indoor air, building ventilation, filtration, humidity, temperature, security, noise, or a specific room.
Complete window · 70/30 rule
Mean + worst hour, stable ties
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The tool compares outdoor air only
After a city is selected, AirAgora evaluates complete two-hour windows from the modeled OpenWeather air-pollution forecast. It preserves the official 1–5 category for display and ranks concentration-band component severity with the deterministic 70/30 rule.
The result is one input to ventilation timing. It does not know indoor pollutant sources, occupancy, cooking, cleaning, combustion, ventilation systems, filters, window orientation, or the air already inside.
Why indoor and outdoor conditions cannot be collapsed
Indoor concentration depends on entry, removal, generation, mixing, and building behavior. A lower outdoor forecast does not prove that opening a window will improve every indoor condition, and a higher outdoor index does not describe the full indoor environment.
AirAgora therefore labels ventilation advice as outdoor-air context only. It does not calculate air changes, filter performance, carbon dioxide, mold, humidity, allergens, or exposure in a specific building.
Complete windows help avoid a rapid outdoor change
A single attractive hour can be followed by a deterioration. Both hours must contain valid selected-index data, and the score keeps 30 percent weight on the worst hour. Missing outdoor fields are not interpolated.
If the best window is only marginally better than the median, the tool says conditions are similar. This avoids making a precise window-opening claim from a tiny modeled difference.
When every outdoor period is elevated
If all complete practical windows are poor or unhealthy under the named scheme, AirAgora may identify the least polluted available period but keeps broad caution visible. It never says that the winning period guarantees suitable ventilation.
During wildfire smoke, dust, industrial incidents, or official warnings, consult local authorities and building-specific guidance. A broad model grid can differ from a plume, road, monitor, or window façade.
A careful ventilation checklist
Confirm the city, OpenWeather 1–5 label, main pollutant from concentration-band severity, source timestamp, modeled status, stale state, and trend across the whole intended period. Then consider the building and indoor factors AirAgora does not observe.
If OpenWeather is unavailable, the production tool reports unavailable rather than substituting fixtures, scraping, or another provider. Browser geolocation remains click-only, and public payloads omit exact coordinates.
- Outdoor forecast is not an indoor measurement.
- Check the full period and source timestamp.
- Consider building, filtration, and indoor sources separately.
- Treat “least polluted” as relative, not suitable-for-every-building.
- Follow official guidance during severe events.
Direct answers
Frequently asked questions
Does AirAgora measure indoor air?
No. AirAgora uses modeled outdoor air-pollution forecast data from OpenWeather only.
Can it tell me exactly when to open a specific window?
No. It compares broad outdoor periods and cannot assess the building, room, window orientation, filtration, or indoor sources.
Why use a two-hour window?
It keeps a change after one attractive hour visible and requires complete data for a practical period.
Does ventilation change the environmental ranking?
No. It changes the caution copy to emphasize that the data describe outdoor conditions only.
What if every outdoor period is poor?
AirAgora can label the least polluted complete period while keeping the whole range elevated and avoiding a ventilation guarantee.
Can local outdoor air differ from the city model?
Yes. The broad grid can differ from a road, façade, monitor, terrain feature, or moving plume.
Evidence register
Sources and further reading
The links below identify the primary references used on this page. Selection, summary, and presentation are AirAgora modifications.
Keep exploring
AirAgora provides informational planning guidance, not medical advice. Local conditions can differ from modeled forecasts; follow official guidance during severe events.